Improvement in device for grinding saw-gtimmer burrs



titled' tant @tutti ermite.

Letters Patent Np. 97,415, dated Nocember 30, 1869.

IMPROVEMENT IN DEVICE ron @BINDING SAW-GUMMER BUI-cus.

The Schedule referred to :in these Letters Patent. andimaking part of the Same.

To all whom (it 'may concern v Be it-known thatI, CHARLES E. Lewis, of North field, in the county of .Washington, and State of Vermont, have invented certain new and useful Improve- Vments in Devices for Grinding Saw-Gummer Burrs,

sure that the cutting-edges of the sameshall have a uniform bevel or taper throughout theinlength, and

4be everywhere equal, one with another, in their distance, radially, from their common axis, while the dey gree of bevel in one set of cutters may be made to vary from that of another set, as the nature of the work performed by them may demand. 'Io this end,

My improvements consist in a light carriage, to which the burr is to be attached, while undergoing the process of grinding, in such a manner as to be easily adjusted to all the requirements of the occasion.

i In the accompanying drawings, which show a convenient arrangement of parts for carrying out the objects of my invention, Y

A represents a light metallic frame, in form of a yoke, or Y, having a handle, a, at the end of its central arm, by which it is held upon the grindstone.

Pendants al, secured to or formed in a piece with the frame A, project downward therefrom at the end of the central arm, and similar pendants, b4, are correspondingly placed at the ends of the side arms. l

A wheel, A1, is mounted in bearings near the lower ends of' the )endants c1 and two wheels b1 b rotate l i 1 a upon a shaft secured to the pendants 1)*,11ear their lower ends.

All` three wheels may be'either fast or loose upon their shaftsaecording as the latter rotate or are made stationary in the pendant-s, as found most convenient.

An arm,- B, is pivot-ed loosely upon the shaft of the wheels b1, and extends toward ythe central arm of the frame A. V y i -A screw, E, is secured to the free end of the arm B, and passes througha slot,'a2, in the frame, being provided with nuts c above and below the same.

By proper movement of the nuts, the arm is raised or lowered, as required.

A carriage, B, is secured to the arm B, by a screw, b2, passing' through a slot, b, inthe same.

By slacking the screw b2, and moving it along the slot, the carriage can be moved toward yor away from the wheels b1. t

C represents a saw-gummer burr, which is of cylindrical form, and provided with a series of cutters c c upon its periphery.

' When the burr is to be ground, it is placed, as shown in the drawing, in the angular recesses b of the peinlants B2, which project below the carriage B1 at the end nearest the wheel Amand is held in position by a spring, D, which bears against one of the cutters c.

The device isv now placed upon a grindstone, as shown in fig. 2, the position of the arm B being regnlated by the screw E and nuts e, so that the wheels b1 and the cutter c to be ground shall bear upon the stone.

The latter is then rotated until the cutter is ground so far that the wheel A will bear upon the grindstone, and prevent further action of the same upon the cut-` ter.

The burr is then turned in'thcrecesses l) until the next cutter is brought into proper position to be ground,

' and the operation i-s repeated and continued in this manner until all the cutters are finished.

The wheel A acts as a gauge, and it will be observed that when a cutter is ground so far as to allow all `three wheels to bear upon the stone, it can be ground no further, except by lowering the arm B.

By this arrangement, the cutters 'are ground in av uniform manner all around the burr, and their depth may be uniformly varied, as desired.,

By moving the carriage Bl toward or from the wheels b, which can be done, as before stated, by means of the screw b'Z and slot b, the angle or bevel at which the cutters are ground can be varied when necessary.

My invention enables a saw-glimmer burr to be ground accurately and uniformly, thus causingv the operation of the same to be more etlicent and satisfactory than when ground by hand', and expediting and simplifying the work of grinding.

What I claim as myv invention, and desire to securel by Letters Patent, is

rlhe frame .A and wheels 11, in combination with the pivoted arm B, longitudinally-adjustable carriage B, screw E, nuts e, and wheel A1,the whole arranged and operating substantially as set forth.

vIn testimony that I claim the foregoing improvements, I have hereunto set my ha-nd, this 25th day ot' March. 1869.

CHARLES IJlW l Witnesses G conce W. Soren, f f CHARLES A. BRAMAN. 

